Adjustable limit means for mining disintegrating mechanism



A. L. BARRETT ADJUSTABLE LIMIT MEANS FOR MINING July 24, 1956DISINTEGRATING MECHANISM 2 Sheets-Shes: 1

Filed Oct. 31 1951 .kann

nnimnwmlwmi Xlummsmmamu July 24, 1956 A. l.. BARRETT ADJUSTABLE LIMITMEANS FOR MINING DISINTEGRATING MECHANISM 2 Sheets-Shea: 2

Filed Oct. 31. 1951 .mmm

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United States Patent O ADJUSTABLE LIMIT MEANS FOR MINING DISINTEGRATINGMECHANISM Arthur Lee Barrett, Franklin, Pa., assignor to `loyManufacturing Company, Pittsburgh, Pa., a corporation of PennsylvaniaApplication October 31, 1951, Serial No. 254,091

17 Claims. (Cl. 262-29) This invention relates to mining apparatus andmore especially to mining apparatus of the so-called continuous minertype.

One well-known continuous miner comprises a portable base provided withsupporting and propelling means and bears upon its base a turntablemechanism upon which there is supported for advance and retraction inradial lines disintegrating mechanism. The disintegrating mechanismincludes a series of chains equipped with disintegrating elements, andis disposable in a downwardly inclined position for sumping, isswingable upwardly, after sumping is completed, to tear loose anddisintegrate a relatively wide strip of coal or other mineral, and isthen movable horizontally rearwardly while in an upwardly inclinedposition 'to complete the removal of an upright band of coal (or othermineral) having substantially par- 7 allel upper and lower edges. Thedisintegrating mechanism has associated with it forwardly disposedmaterialreceiving and handling arrangements for delivering thedisintegrated material adjacent the center of the turntable, anddesirably other conveying arrangements are provided to transport thedisintegrated material from the central portions of the turntable to anappropriate point of discharge. rEhe sumping and withdrawing isaccomplished by hydraulic cylinder and piston mechanisms, as also isupswing, these hydraulic mechanisms providing for great precision ofcontrol. Other miners have walking type supporting and moving means andare sumped and withdrawn by bodily advance and retraction, andy havesocalled open center bars with side chains and central drums providedwith cutter bits, but the method of rectilinear suniping, swinging invertical planes, and rectilinear retraction are features common to theusual operation oi miners of both types.

lt is desirable to maintain the bottom and top (the floor and roof) ofthe working place approximately level, and it is desirable to be able toalter the level of the iloor and/or of the roof as the thickness of theseam and/or its inclination vary. lt is therefore desirable to providean arrangement which will permit adjustable control of the limits of theswinging movement of the disintegrating apparatus-not only the lowerlimit but the upper limitand to have such arrangements include meanswhich automatically interrupt the movements of the disintegratingapparatus when the latter attains to the desired limit positions chosenfor particular operating conditions. .lt is further desirable to provideadjustment-effecting arrangements equipped with devices enabling quickand easy change of the level of the prospective floor or roof, or both.It is further desirable, in order that it may be used conveniently withapparatus which may not already be provided with such adjuncts orcomponents, to make the apparatus of such a type and character that itmay be incorporated in the upswing effecting or downswing controllingmeans of a miner already in the field, with a minimum of change.

lt is au object of my invention to provide an improved mining apparatushaving incorporated in it improved Ind means for controlling a limit ofa vertically swingable coal or other mineral-attacking instrumentality.lt is another object of my invention to provide an improved adjustablelimit device for a vertical swing mechanism of a continuous miner. It isa further object of my invention to provide improved adjustable limitdevices for each of the vertical swinging operations of a continuousminer. lt is still another object of the invention to provide animproved hydraulically controlled adjustable limit mechanism for usewith the hydraulically swung disintegrating devices of a continuousminer. lt is yet a further object of the invention to provide animproved, readily adjustable limit means for controlling the range ofthe movement of a hydraulic motor actuated disintegrating mechanism.Broadly, it is an object of the invention to provide improved limitmeans for use with vertically swingable apparatus which it is desirableto have brought to rest upon the attainment of a predetermined position.Other objects and advantages of the invention will hereinaftr 1.11ct@fully appear.

ln the accompanying drawings, in which one illustrative embodiment ofthe invention is shown for purposes of illustration, f

Fig. l is a plan view, and Fig. 2 is a side elevational view of theforward end of one form of mining apparatus of the continuous minertype.

Fis. 3 iS a horizontal sectional View, withy parts omitted, on theapproximate plane of the line 3.-.-3 of Fig. 2,. This view is includedprincipally to show the sumping and withdrawing arrangements.

Fig. 4 isa detail central section on an enlarged scale ythrough anadjustable chamber device forming apart of the illustrative embodimentof the invention.

Fig. 5 is a detail vertical sectional View on an enlarged scale'througha portion of a mechanism which is provided to effect the automaticreturn of a control element to neutral position when the device which itcontrols reaches either ,of two predetermined positions.

Fig. 6 is a diagrammatic view of a control mechanism in which theinvention is embodied in its illustrative form.

Fig, 7 is an enlarged, diagrammatic view, partially in section, of aportion of the'apparatus shown in Fig. 6.

Fig. 8 is a detail elevational view of a disintegrating apparatusswinging mechanism.

Referring now to the accompanying drawings, the forward end of acontinuous mining apparatus 1 is shown in Figs. l and 2. This apparatusincludes a suitably sup.- ported and movable base 2 herein shown assupported on tractor treads 3. The base is shown as carrying a turnable,4 rotatable about a Vertical axis 5 (see Fig. l) and carrying,reciprocably mounted thereon, a frame 7 carrying'a disintegratingmechanism 8, which is herein in the form of a swinging arm structure.The turntable 4 supports a pair of laterally spaced disintegratingmechanism driving motors 9 connected by extensible shaft means 10 withgearing, not shown, in gear housings 11 mounted on and forming a part ofthe reciprocable frame 7. This gearing drives the disintegratingapparatus 8, which, as shown herein, includes a'series (six are shown)of disintegrating chains 13 which are adapted to circulate about aswingable support 14.

The disintegrating mechanism is vertically swingable about a horizontalaxis 15 on the frame 7, and may be swung upwardly about the axis 15 bymechanism which includes a pair of single-acting hydraulic cylinder andpiston mechanisms 20, 20. Each of these includes a cylinder element 21secured to one side of the frame structure 14 and having a bore 22.Pistons 23, suitably packed, are-reciprocably mounted in the bores 22.Secured to the opposite sides of the vframe structure 14 at pointsnearer its free end than are the cylinder elements Z1 are downwardlyextending brackets 24 which have pivotally conananas nected to them atthe forward ends of rearwardly extending lever elements or reactionmembers 26. The members 26 carry brackets 27to which there are pivotallyconnected by `pins 28 the lower ends of connecting rods 29, the upperends of which are pivotally connected at 30 to the pistons 23, which arereciprocable in the bores 22 of the cylinder elements 21.` Therearwardends of the lever elements 26 have upwardly extending short arms32 to which there are connected at 33 llexible chains 34 which, at theirother ends, are secured as at 35 to the upper sides of curved forwardends 36 of a gear casing and frame structure 37 which pivotally supportsthe disintegrating mechanism and houses the drive for the chains 13 ofthe latter. The cylinder elements 21 each have a oommon uid supply anddischarge connection, these `being designated 39 for one of the same and40 forthe other (see Fig. 6). When fluid is supplied to the cylinderbores 22 above the pistons 23, the frame structure 14 is swung upwardly,and when lluid is vented from the spaces mentioned the frame structureswings downwardly about the pivot 15, of its own weight. As will laterbe explained, fluid is supplied to the cylinders 21 simultaneously, andit is also vented from these cylinders simultaneously, there beingconduits 42 and 43 extending from a common supply and bent conduit 44and connected with the common supply and discharge connections 39 and40. In a manner later to be described, fluid may be supplied to theconduit 44 to effect `upswing of the disintegrating mechanism, andvented from the conduit 44 to permit downswing of the disintegratingmechanism, and this supplying and venting is controlled by a manuallyoperable valve device generally designated 46, of which more will besaid later.

Before describing the adjustable limit means it may be worth-whilebriefly to describe the sumping and'withdrawing feature of thecontinuous miner illustrated. As shown in Fig. 3 sumping and withdrawingmovements of the disintegrating apparatus will be etected by mechanismincluding cylinders 51 and 52. These contain pistons 53, 54 connected bypiston rods 55 and 56 `with brackets 57 attached to the frame 7. Thecylinders 51 and 52 and their associated pistons form double-actingmotors, and `iuid `may be supplied to their opposite ends throughconduits 59 and 60, supply to the conduit 60 effecting withdrawalmovement. t

As the sumping and withdrawing movements effected by the cylinder andpiston mechanisms 51, 53, and 52, 54, and the upswing movement of themechanism 8 are all hydraulically accomplished a reservoir 62 isprovided for hydraulic uid. This reservoir is connected by a conduit 53to a pump 64 which discharges to a conduit 65 opening into an endelement 66 of a valve box structure of the valve device 46. The valvebox structure includes another end element 68 and a pair` ofyintermediate valves boxes 69 and 70.` The valve box 69 contains a valve71, diagrammatically shown, and controlled by an operating handle 72,and controlling the supply of lluid through the conduits 59 and 60 andthe venting of fluid from these same conduits and back to the reservoir62 through a return conduit 73. The conduit`59 is connected lby aconduit 75 under the control of a pressure relief valve 76 with a returnconduit 77 leading back to the tank or reservoir 62. In like manner theconduit under the control of a pressure relief valve 78 is adapted topermit the return of hydraulic fluid through a conduit 79 and theconrluit 77 to the reservoir 62. The purpose of the relief valves 76 and78 is to prevent excessive pressures being exerted by the sumping andwithdrawing mechanism.

It maybe noted that the conduit 44 is connected under the control of apressure relief valve 81 land through'a drain conduit 82'with theconduit 73, so that if there should be a roof fall upon thedisintegrating mechanism when the latter was in raised position,thedisintegrating mechanism could be depressed by the weight upon it,following displacement of fluid from the cylinders 21, 21 hrough theconduits 42 and 43 and the conduit 44, pres- 73. It may be noted thatthe end element 66 may have a relief valve incorporated in it in acustomary manner, though the same is not believed to be necessary toillustrate in the drawing. When the valves in the valve boxes 69 and 70are in mid-position, uid is not supplied to any servomotor mechanism andthe uid tlows freely from the conduit to the conduit 73 and back to thetank 62 in a well known manner. The valve element 71. is movabledownwardly in Fig. 6 to supply uid to the conduit 60, and is movableupwardly in Fig. 6 to supply fluid to the conduit 59. The valve boxcontains a valve element having an operating handle 91. On movement ofthe handle 91 downwardly in Fig. 6 to move the valve element 90downwardly from mid-position, fluid is vented from the cylinder andpiston mechanisms 20, 20 and the disintegrating apparatus 8 is thereforefree to swing downwardly. When the valve element 90 is moved upwardlyfrom mid-position in Fig. 6 iluid will be supplied to the cylinder andpiston mechanisms 20, 20 to effect upswing of the disintegratingapparatus. Whenever the valve element 90 is brought to mid-position itwill automatically interrupt whichever movement, up or down, thedisintegrating apparatus may be in process of making.

The foregoing description makes it possible now effectively to considerthe adjustable motion limiting devices. These are hydraulically operatedand they effect their limiting of movement of the disintegratingapparatus through the bringing of the valve element 90 to its mid orneutral position. Referring to Fig. 5 it will be observed that theoperating element 91 has extending laterally from it an arm 95terminating in oppositely extending portions 96 and 96". It will beobserved that when the operating element 91 is moved downwardly in Fig.5 the portions 96 and 96 will be moved downwardly. When the element 91is moved upwardly from mid-position the portions 96' and 96" will bemoved upwardly from the position shown in Fig. 5. Servo-mechanisms 101and 102 suitably mounted, as represented by fragments of brackets 103and 103", are arranged in such conjunction with the portions 96 and 96"that they may actuate whichever one of these portions is displacedtowards the servo-mechanism which cooperates with it and return therebythe operating element 91 and the valve 90 to neutral or mid-position.Each of the servo-mechanisms includes, as illustrated, a tubular body105 having a bore 106, in which a hollow guide element 107 isreciprocably guided, this guide element having a nose 108 adapted toengage, in the case of servo-mechanism 101, the portion 96', and in thecase of the servo-mechanism 102 the portion 96". Springs 110 act betweenthe nearer ends of the elements 107 and shoulders 111 and normallymaintain the elements 107 as it were retracted The elements 107 may beforced towards each other by plungers 112 guided in cylinders 113 and114 carried by the members 105. The cylinders 113 and 114 and plungers112 are but representative of any suitable relatively leakage-freeexpansible chamber devices which may be used for the movement of theelements 107 in a direction to move the valve 90 to mid-position. It maybe noted that when the nose portions 108 are spacedfrom each other theirmaximum permitted distance, they will be equally spaced from theportions 96' and 96" when thc valve element 90 is in mid-position. Thetravel of the portions 96 and 96", as the valve 90 is moved to itsdifferent operating positions, is such as to bring these portions intoposition for engagement by the nose portions 108 so that such noseportions can effect the return of the valve 90 to mid-position. Theamount of free movement of the nose portions is only such as will suticeto return the valve 90 to mid-position, and the valve 90 can be movedits full travel in either direction from mid-position without therebeing obstruction of the movement of the portions 96' or 96" by the noseportions 108 when the letter are in retracted position. The springs arecomparatively stiff as will later appear, and for reasons which willshortly be explained. Fluid may be admitted to the cylinder 113 of theservo-motor mechanism 101 through a conduit 121, and through a conduit122 to the cylinder 114 of the servo-mechanism 102.

The disintegrating mechanism swing controlled devices for supplyingfluid to the servo-mechanism cylinders 113 and 114 may now be described.Each includes a fluid displacement apparatus 125. These may be madealike, for economy in number of manufactured parts, or in the interestof simplicity of actuation may be different from each other. Herein theywill be illustrated as essentially alike, and each, as shown, includes acylinder 126, a piston 127, and a piston rod 128. The cylinders 126 maybe supported by the frame 14, and herein are shown as pivotallysupported by the latter at 129. The piston rods are operativelyconnected, in the arrangement shown, to the lever elements 26, as thereis relative movement between the bar and the lever elements during upand down swing, the angle between these elements increasing duringupswing and decreasing during lowering or downswing. As it is desiredthat one of the iluid displacement apparatuses displace fluid duringupswing and the other during downswing the connections between thepiston rods 128 and the lever 26 will be appropriately selected. Todistinguish between the upswing and downswing controls all of the partsbearing like numerals are distinguished by letters: U for upswing and Dfor downswing or lowering.

Apparatus 125D, the uid displacement apparatus f relation, having inmind the pivotal mounting at 129.

If the device 125D were solidly Xed to the frame 14, the piston rod 128Dmight simply engage at a proper time an abutment surface on the lever26.

Apparatus 125U is intended to have its piston 127U displaced upwards asthe other lever 26 (there is one at each side of the disintegratingmechanism) moves away from the frame 14, so the piston rod 128U isconnected as shown, by a double bell crank mechanism 134 and a dependinglink 135 ending in an elongated eye 136, with a pin 137 on the otherlever, so as to get the desired motion. The double bell crank mechanismcomprises bell crank elements 138 and 139 pivotally mounted on one sideof the frame 14 on pivots 140 and 141 respectively, and pivotallyconnected together, with necessary play, at 142. Evidently, with thisarrangement the device 125U will displace fluid as the bar or frame 14is raised.

The apparatus 125U and associated parts are shown in Fig. 8.

There have now been described two devices 125U and 125D which whensupplied with fluid will take in an ini.

creased volume when actuated in one direction and displace it whenactuated in the other` direction, each displacing iuid when thedisintegrating mechanism is moved in a direction opposite to that whichwill cause the other to displace fluid.

The iluid displaced by the devices 125U and 125D is what makes theservo-mechanisms 101 and 102 selectively operative.

It may be noted that each piston 127 is normally pressed downwardly inyits cylinder 126, wherefore each device 125D or 125U normally tends tobe as full of iluid as the relative position of its parts permits.Springs 145 normally maintain the pistons as far down in their cylindersas possible, and tend to return them to their bottom positions.

` A source of fluid, herein shown as a tank 150 desirably located higherthan either of the devices 125U and 125D, is provided as a supply forfluid to the devices 125U and 125D. From the tank l150 a conduit 151,having in it a check valve 152 opening towards `the device 125U, eX-

6 tends to the top of the cylinder 126U. This prevents air binding. Ifexcessively high pressure is caused to exist in the conduit 151 it maybe relieved by by-pass connection 153 having a properly set relief valve154 in it and leading back to the tank 150. The conduit 151 is connectedby conduit means 155 with the conduit means 121. The conduit means 155has connected with it a variable capacity device 156 herein shown asincluding a chamber forming casing 157 providing a chamber 158 whichserves as a connection between spaced portions of the conduit means S.Within the chamber 158 of the casing 157 there is mounted a bellowsdevice 159. This bellows device may be of any suitable form and issupported by a cover 160 for the casing 157. The top of the bellows issecured to and hermetically sealed relative to the inside surface of thecover 160 and the cover 160 is sealed relative to the casing 157. Anadjustable stop 161 is arranged to limit the collapsing movement of thebellows 159 and is threadedly mounted at 162 in the cover 160 and has anend 163 adapted to be engaged by the head 164 of the bellows 159. Itwill be evident that as uid is displaced by upward movement of thepiston 127U and is forced away from that fluid displacing means throughthe conduits 151, 155 it cannot return to the tank 150 past the checkvalve 152, and the relief valve 154 is set too high to permit thedisplaced fluid to pass through The uid displacement device D isconnected with the tank by a conduit 151', which has a relief valve(154') controlled by-pass connection 153 with the tank and whichcontains a check valve 152. The conduit 151 is connected by a conduithaving between its ends another variable capacity device 156', with theconduit 122 leading to the servo-mechanism for returning the valve 90 tomid-position when the desired lower limit of the disintegratingmechanism is reached.

It will be evident that when either of the pistons 127 is displacedupwardly in its cylinder 126 fluid will be displaced from such cylinderand will be forced in the direction of one of the valve-centeringservo-mechanisms. It will produce no movement of the respectiveservomechanism, however, to restore the valve 90 to mid-position untilafter the connected variable capacity device 156 or 156 has had itscollapsible bellows compressed as far as the stop screw 161 permits. Itwill be evident that by varying the adjustments of the stop screws thepoints at which the control valve 90 will be returned to centralposition will be altered. It will be evident that, if desired, theinherent resilience of the collapsible bellows 159 can be augmented by aspring housed within the bellows. The resistances to movement of therelatively moving elements will be made such that the bellows devices159 will be compressed before there is any valve centering movement ofthe servo-motor devices 101 and 102, and the setting of the reliefvalves 154 and 154 will be such that these will not open until a muchhigher pressure is produced than is necessary to recenterV the valveelement 90. It will be evident that through the provision of the devices156 and 156 there may be greater or smaller movements of the piston 127relative to the cylinder 126 before the valve 90 will be returned fromany of its displaced positions to mid-position, and accordingly that theupper and lower points at which the disintegrating mechanism will haveits movements stopped are readily variable.

From the description which has been given it will be apparent that lhave illustrated devices for limiting the swing of an arm or boomelement in either direction, said devices including what amounts to apump, a servomotor controlling the movement of said boom or arm, andactuated by iluid supplied by the pump, and means for delaying asdesired the actuation of the servo-motor by the uid delivered by thepump, consisting of means variable in volume at will for receiving theiiuid discharged by the pump, at pressures less than sutcient to operatesaid servo-motor, until a desired instant for actuation of saidservo-motor arrives. There is a mechanism of the `character mentionedfor limiting each of the opposite movements of the boom or arm. Thepumplike devices are respectively adapted, in the construction chosenfor purposes of illustration, to be `actuated by a thrust produced uponrelative movement between certain `parts and by a tension or tractionexerted by opposite relative movement between said parts. The pumpdevices are adapted to be automatically self-filling, and the controlsystems are automatically protected by relief valves set at pressureshigher than the pressures necessary to operate the servo-motor, whilethe pressures necessary to operate the servo-motors exceed the pressuresnecessary to effect yielding of the adjustable accumulator-like deviceswhich serve as timers for the exercise of the controls;

The arrangement may obviously have either half thereof employed withoutthe other as desired, and the whole is simple, positive in operation,adjustable with precision,

, and results in not only a stopping of the element whose movements areto be limited at precise points desired, but to lock the adjustedelement in its selected limit positions, for the valve 90 inmid-position is adaptedy to seal pressure within the cylinders21,`subject however,ito.the automatic control exercised by the pressurerelief valve 81 in the event of a roof fall, or the like.

While there is in this application specilically described one form whichthe invention may assume in practice, it will be understood that thisform of the same is shown for purposes of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim is:

l. In combination, a support, an arm structure pivotally supported onand swingable relative to said support, hydraulic mechanism foreffecting such swinging, valve means for controlling the operation ofsuch hydraulic mechanism including a valve device, means for moving said`valve device to elfect swinging of said arm structure by said hydraulicmechanism, and means for moving said valve device to interrupt swingingwhen said arm structure reaches a desired position including a uiddisplacement device actuated upon swinging of said arm structure, avariable capacity chamber, and a uid operable servo-mechanism foreffecting the last mentioned movement of said valve device, saidvariable capacity chamber having a wall movable to vary its volume andyieldable at a pressure below that requisite to initiate operation ofsaid uid operable servo-mechanism and means for connecting said fluiddisplacement device, said variable capacity chamber and saidservo-mechanism all in communication with each other.

2. In combination, a support, an arm structure pivotally supported onand swingable relative to said support, hydraulic mechanism foreffecting such swinging, valve means for controlling the operationofsuch hydraulic mechanism including a valve device, means for moving saidvalve device to effect swinging of said arm structure by said hydraulicmechanism, and means for moving said valve device to interrupt swingingwhen said arm structure reaches a desired position including a uiddisplacement device actuated upon swinging of said arm structure, avariable capacity chamber, and a liuid operable servo-mechanism forreecting the last mentioned movement of said valve device, and means forconnecting said fluid displacement device, said variable capacitychamber and said servo-mechanism all in communication with each other,said variable capacity chamber having a limitedly movable wall yieldablefor the full distance available to it at a pressure below that requiredto initiate operation of said servo-motor.

3. In combination, a support, an arm structure pivotally supported onand swingable relative to said support,

fill

hydraulic mechanism for effecting such swinging, valve means forcontrolling the operation of such hydraulic mechanism including a valvedevice, means for moving said valve device to effect swinging of saidarm structure by said hydraulic mechanism, and means for moving saidvalve device to interrupt swinging when said arm structure reaches adesired position including a fluid displacement device actuated uponswinging of said yarm structure, a variable capacity chamber, and a uidoperable servo-mechanism for effecting the last mentioned movement ofsaid valve device, and means for connecting said fluid displacementdevice, said variable capacity chamber and said servo-mechanism all incommunication with each other, said variable capacity chamber having amovable bounding wall and means for limiting its movement to differentpredetermined distances.

4. In combination, a support, an arm structure pivotally supported onand swingable relative to said support, hydraulic mechanism foreffecting such swinging, valve means for supplying pressure to effectthe operation of such hydraulic mechanism including a valve device,means for moving said valve device to effect tiuid supply to causeswinging of said arm structure by said hydraulic mechanism, and meansfor moving said valve device to interrupt uid supply when said armstructure reaches a desired position including a tiuid displacementdevice actuated upon swinging of said arm structure, a variable capacitychamber, and a fluid operable servo-mechanism for effecting the lastmentioned movement of said valve device, said variable capacity chamberhaving a wall movable to vary its volume and yieldable at a pressurebelow that requisite to initiate operation of said fluid operableservo-mechanism and means for connecting said uid displacement device,said variable capacity chamber and said servo-mechanism all incommunication with each other.

5. In combination, a support, an arm structure pivotally supported onand swingable relative to said support, hydraulic mechanism foreffecting such swinging, valve means for controlling the operation ofsuch hydraulic mechanism including a valve device movable to vent fluidfrom said mechanism to permit swinging thereof, means for moving saidvalve device to uid venting position, and means for moving said valvedevice to interrupt venting when said arm structure reaches a desiredposition including a fluid displacement device actuated upon swinging ofsaid arm structure, a variable capacity chamber, and a fluid operableservo-mechanism for etfecting the last mentioned movement of said valvedevice, said variable capacity chamber having a wallmovable to vary itsvolume and yieldable at a pressure below that requisite to initiateoperation of said uid operable servo-mechanism and means for connectingsaid fluid displacement device, said variable capacity chamber and saidservomechanism all in communication with each other.

6. In combination, a support, an arm structure pivotally supported onand swingable relative to said support, hydraulic mechanism foreffecting such swinging, valve means for controlling the operation ofsuch hydraulic mechanism including a valve device having a mid-positionin which said hydraulic mechanism is cut otf from both supply andexhaust, and mutually opposite positions in which said mechanism isconnected for uid supply and for fluid exhaust respectively, means formoving said valve device to either of its mutually opposite positions,and means for moving said valve device to midposition when said armstructure reaches either a desired upper or a desired lower positionincluding, individual to each control, a fluid displacement deviceactuated upon swinging of said arm structure in one direction, avariable capacity chamber, and a uid operable servo-mechanism foreffecting the last mentioned movement of said valve device, saidvariable capacity chamber having a wall movable to vary its volume andyieldable at a pressure below that requisite to initiate operation ofsaid tiuid operable servo-mechanism and means for connectmg said fluiddisplacement device, said variable capacity chamber and saidservo-mechanism all in communication with each other. a 7. In acontinuous mining apparatus, a support, a disintegrating apparatushaving a supporting frame pivotally mounted on said support to swing invertical planes, power operated mechanism for swinging saiddisintegratlng apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating fluid to said cylinder and piston mechanismincluding a iluid receiving chamber of optionally variable capacitypreset before the initiation of such supply and, in communication withsaid chamber, a fluid displacement device carried by said disintegratingapparatus supporting frame and comprising a pump actuated by therelative movement between said frame and said lever.

8. Inv a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotally mounted on said support toswing in vertical planes, pow- 'er operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controllingventing of operating fluid from said cylinder and piston mechanismincluding a iluid receiving chamber of optionally variable capacitypreset before the initiation of such supply and, in communication withsaid chamber, a fluid displacement device carried by said disintegratingapparatus supporting frame and comprising a pump actuated by therelative movement between said frame and said lever.

9. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotally mounted on said support toswing in vertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply and venting of operating fluid relative to said cylinder andpiston mechanism including, individual to each control, a fluidreceiving chamber of optionally variable capacity preset before theinitiation of such supply and, in communication with said chamber, a uiddisplacement device carried by said disintegrating apparatus supportingframe and comprising a pump actuated by one of the relative movementsbetween said frame and said lever.

l0. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotal- 1y mounted on said supportto swing in vertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating fluid to said cylinder and piston mechanismincluding a iluid receiving chamber of optionally variable capacitypreset before the initiation of such supply and, in communication withsaid chamber, a device carried by said disintegrating apparatussupporting frame and comprising a pump actuated by that relativemovement between said frame and said lever which reduces the meanspacing between them.

11. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame'piv'otally mounted on said supportto swing in vertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot includingatleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating fluid to saidcylinder and piston mechanism includinga fluid receiving chamber of optionally variable capacity preset beforethe initiation of such supply and, in communication with said chamber, adevice carried by said disintegrating apparatus supporting frame andcomprising a pump actuated by that relative movement between said frameand said lever which increases the mean spacing between them.

12. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotally mounted on said support toswing in vertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply and venting of operating fluid relative to said cylinder andpiston mechanism including devices carried by said disintegratingapparatus supporting frame and comprising pumps actuated one by theincrease and the other by the decrease of the mean distance between saidpivotally mounted disintegrating apparatus supporting frame and saidlever and furtherincluding nid receiving chambers of optionally variablecapacity preset before actuation of means for controlling is initiated,one in communication withthe discharge of each of said pumps.

13. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotally mounted on said support toswing in vertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating fluid to said cylinder and piston mechanism including a valve movable from a closed to an open position toetfect'power swinging of said disintegrating apparatus and means forautomatically returning said valve to its closed position including afluid receiving chamber of optionally variable capacity preset beforethe initiation of such supply, and in communication with said chamber, adevice for generating a valve moving force carried by saiddisintegrating apparatus supporting frame and comprising a pump actuatedby relative movement effected by power between said frame and saidlever.

14. In a continuous mining apparatus, a support, a disintegratingapparatus having a supporting frame pivotally mounted on said support toswing in kvertical planes, power operated mechanism for swinging saiddisintegrating apparatus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating uid to said cylinder and piston mechanism includinga valve movable from a closed to a venting position to eifect gravityswinging of said disintegrating apparatus and means for automaticallyreturning said valve to its closed position including a uid receivingchamber of optionally variable capacity preset before the initiation ofsuch supply and, in communication with said chamber,

a device for generating a valve moving force carried by saiddisintegrating apparatus supporting frame and comprising a pump actuatedby the relative movement between said frame and said lever which occursduring gravity swinging of said disintegrating apparatus supportingframe.

1S. In a continuous mining apparatus, a support, a disintegratngapparatus having a supporting frame pivotally mounted on said support toswing in vertical planes, power operated mechanism for swinging saiddisintegrating ap paratus supporting frame about its pivot including atleast one lever pivotally connected to said disintegrating apparatussupporting frame and connected also to said support and hydrauliccylinder and piston mechanism acting between said lever and saiddisintegrating apparatus supporting frame, and means for controlling thesupply of operating fluid to said cylinder and piston mechanismincluding a valve movable from a closed to an open position to effectswinging of Said disintegrating apparatus supporting frame and `meansfor automatically returning said valve to its closed position includinga valve moving servomotor, a device carried by said disintegrating`apparatus supporting frame and comprising a pump actuated by relativemovement between said frame and said lever for supplying duid underpressure for the actuation of said servo-motor and means for delayingthe actuation of said servo-motor by fluid so supplied includingchamber-femm ing means for receiving and maintaining, at a pressure lessthan is required for the actuation of said servo-motor, tluid initiallysupplied by said device.

16. In combination, a support, an arm structure supported on and movablerelative to said support, hydraulically controlled mechanism forcontrolling such relative movement, valve means for controlling theoperation of such hydraulically controlled mechanism including a valvedevice open during the occurrence of such relative movement, and lmeansfor moving said valve device to interrupt such relative movement whensaid arm structure reaches a desired position including a Huiddisplacement device actuated upon movement of said arm structurerelative to said support, a variable capacity chamber, and

a fluid operable servo-mechanism for effecting closure of said valvedevice, said variable capacity chamber having a wall movable to vary itsvolume and yieldable at a pressure below that requisite to initiateoperation of said fluid operable servo-mechanism and means forconnecting said fluid displacement device, said variable capacitychamber and said servo-mechanism all in communication with each other.

17. ln combination, a support, an arm structure supported on and movablerelative to said support, hydraulically controlled mechanism forcontrolling such relative movement, valve means for controlling theoperation of such hydraulically controlled mechanism including a valvedevice movable between open and closed positions and occupying one ofsaid positions during the occurrence of such relative movement, andmeans for moving said valve device to interrupt such relative movementwhen said arm structure reaches a desired position including a fluiddisplacement device actuated upon movement of said arm structurerelative to said support, a variable capacity chamber, and a iluidoperable servo-mechanism for effecting movement of said valve device tothe other of its positions aforesaid, said variable capacity chamberhaving a wall movable to vary its volume and yieldable at a pressurebelow that requisite to initiate operation of said uid operableservo-mechanism and means for connecting said uid displacement device,said variable capacity chamber and said servo-mechanism all incommunication with each other.

References Cited in the tile of this patent UNITED STATES PATENTS752,491 Warren Feb. 16, 1904 858,207 Patten June 25, 1907 884,960 SuiterApr. 14, 1908 897,907 Lang Sept. 8, 1908 2,303,752 Meredith Dec. 1, 19422,456,236 Acton Dec. 14, 1948

